Shark resistant composite fabric

ABSTRACT

The present invention discloses a shark resistant composite fabric that has an outer layer of a woven or knitted shark bite resistant fabric material; an intermediate layer neoprene. An inner layer of a woven or knitted shark bite resistant fabric material may also be provided.

TECHNICAL FIELD

The present invention relates to fabrics for use in wetsuits and similarapplications, and to garments and other objects formed using suchfabrics.

BACKGROUND OF THE INVENTION

Divers, surfers and other water users are subject to the risk of attackby a shark. Most attacks are by a small subset of shark species,primarily bull, tiger and great white sharks. A variety of strategies,electronic shark shielding devices, chemical deterrents and otherproposals have been made to reduce the risk of shark attack. These havehad varied but generally limited effectiveness.

It has also been proposed to alter a wetsuit, so as to make the wearerless likely to be perceived as food by the shark, including camouflagepatterns, stripes and other patterns.

Other approaches to wetsuit design have affixed rigid plates to parts ofthe wetsuit, in an attempt to prevent bite injuries. For example, U.S.Pat. No. 4,356,569 by Sullivan discloses a shark deterring suit with abase garment which is either chain mail or rubber foam wetsuit materialwith imbedded multiplicity of hard shield elements. U.S. Pat. No.3,284,806 by Prasser discloses a protective body garment that has a foamrubber with a metallic reinforcement and metallic mesh for reinforcementwith the mesh.

U.S. Pat. No. 4,833,729 by Fox discloses a shark protector suit that hasa plurality of spikes to prevent a shark from clamping its jaws over thewearer.

However, these wetsuit designs have not been purchased or not wornbecause they are heavy, expensive to manufacture, and imposed difficultyfor the wearer's movements.

US Patent Application No 20130091610A by Hennessey discloses a wetsuithaving an inner layer of neoprene, an ultra-high molecular weightpolyethylene woven material, a bittering agent (denatonium benzoate)layer and another outer layer of neoprene.

US Patent Publication No. 2008/0289087 A1 by Sundnes discloses a garmentfor use with wetsuits that has a layer of elastic material and at leastone layer of protective element(s).

It is an object of the present invention to provide an improved sharkresistant material for use in wetsuits and similar applications.

SUMMARY OF THE INVENTION

In a first broad form, the present invention provides a compositematerial with an outer layer of a woven or knitted ultra high molecularweight polyethylene (UHMwPE) material, an intermediate layer ofneoprene, and an inner layer of woven or knitted UHMwPE.

According to one aspect, the present invention provides a sharkresistant composite fabric including an outer layer of a woven orknitted shark bite resistant fabric, material, an intermediate layer ofneoprene and an inner layer comprising a shark bite resistant material.

According to another aspect, the present invention provides a sharkresistant composite fabric with an outer layer of a woven or knittedshark bite resistant fabric material and an inner layer of neoprene

According to another aspect, the present invention provides a sharkresistant composite fabric for use in a garment so that during a sharkattack, a contact of the shark's tooth with an outer layer of woven orknitted UHMwPE material resists or deters the completion of a test bite.

Implementations of the present invention allow for a wetsuit which hastwo distinct modes for resisting shark attack. First, in a test orexploratory bite mode, sharks find the texture and feel of the outerlayer unsatisfactory, and in some cases cease their attack at thatstage. Second, even if an attack successfully penetrates the outerlayer, it has been observed that the penetration of the inner layer isunlikely, particularly as it is spaced apart from the outer layer by theneoprene intermediate layer.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present invention will now be describedwith reference to the accompanying figures, in which:

FIG. 1 is a cross-sectional view of one implementation of a fabricaccording to the present invention;

FIG. 2 is a cross-sectional view of another implementation of a fabricaccording to the present invention;

FIG. 3 is a perspective view of a wetsuit made from the fabric of FIG. 1or FIG. 2;

FIG. 4a shows a single shark tooth in initial contact with the fabric ofFIG. 1; and

FIG. 4b shows a single shark tooth depressed into the fabric of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be described with reference to specificimplementations. However, it will be understood that it is contemplatedthat alternative implementations may employ additional features. Forexample, additional layers of material may be employed in specificlocations; an inner lining or neoprene or other material may be added;and the thickness of the neoprene may be varied corresponding to watertemperature or other conditions in the body of water where the suit isto be used. It could also be used in conjunction with a camouflaged orotherwise patterned outer surface.

It will be understood further that while specific details such asmaterials, and dimensions are provided, these are intended asillustrative and not limitative of the possible ways in which thepresent invention could be implemented.

The present implementation contemplates a generally conventional wetsuitin form, with full length legs and arms. However, the fabric can clearlybe incorporated into other garments or wetsuit shapes and styles asrequired, including boots and hoods.

FIG. 1 shows a cross-sectional view of a fabric 10 according to a firstimplementation of the present invention. The fabric 10 has an outerlayer of a woven or knitted ultra high molecular weight polyethylene(UHMwPE) material 11, an intermediate layer of neoprene 15, and an innerlayer of woven or knitted UHMwPE material 13. The layer of neoprene 15is located between the outer layer of woven or knitted UHMwPE material11 and the inner layer of woven or knitted UHMwPE material 13. The outerand inner layers of woven or knitted UHMwPE material 11,13 in thisimplementation have a thickness of 1.2 mm. The intermediate layer ofneoprene 15 has a thickness, in the range of about 1 to about 7 mm, forexample. A typical value is 3 to 5 mm. The intermediate layer ofneoprene 15 is attached to the outer and inner layers of woven orknitted UHMwPE material 11,13 by gluing, heat fusing, or any suitableprocess. A suitable approach is the use of adhesives typically used inthe construction of wetsuits.

In another implementation as shown in FIG. 2, a fabric 40 has an outerlayer of a woven or knitted ultra high molecular weight polyethylene(UHMwPE) material 41, and an inner layer of neoprene 45.

In another implementation, the outer and inner layers 11,13 of thefabric 10 and the outer layer 41 of the fabric 40 comprise a woven orknitted layer of UHMwPE material, fiberglass and polyester. Preferably,the woven or knitted outer and inner layers 11,13 of the fabric 10 andthe outer layer 41 of the fabric 40 have a composition of 42% UHMwPEmaterial, 31% polyester and 27% fiberglass. The properties of thiscomposition of woven or knitted outer and inner layers 11, 13 of thefabric 10 and the outer layer 41 of the fabric 40 are shown in the tablebelow.

Material Composition UHMWPE 42% Polyester 31% Fiberglass 27%Specification Structure Packing Method knit Construction Roll Item UnitStandard Tolerance Test method Properties Weight g/m² 510 ±35 ASTM D3776Width in  62 Min. ASTM D3774 Thickness mm   1.2 ±0.2 ASTM D1777 TensileStrength kg/in L:100 W:35 Min. ASTM D5035 Tearing Strength kg L:18 W:22Min. ASTM D2261 Elongation Rate % L:40 W:200 Min. ASTM D5035 AbrasionResistance Cycle 600 Min. EN388 6.1 Abrasion Resistance Cycle 600 Min.ASTM D3884 Cut Resistance Level  5 Min. EN388 6.2 Cut Resistance ANSIRating A6 Min. ASTM F2992 Puncture Resistance Level  4 Min. EN388 6.4

The UHMwPE material is selected from any suitable commercial material,for example Dyneema® and Spectra®. Dyneema is commercially availablefrom DSM, UHMwPE.(https://www.dsm.com/products/dyneema/en_GB/techndogies/dyneema-form-factors.html).

Spectra is commercially available from Honeywell and an UHMwPE fiberthat is claimed to be stronger and lighter than other ingredient fibers.It is created using a gel-spinning process, which forms long orientedmolecular chains as the fiber is drawn.(http://www.spectra-fiber.com/science-behind-spectra-fiber/).

FIG. 3 shows a wetsuit 20 made from the fabric 10,40. The wetsuit 20 hasa closable opening 21, expansive connections at the panel seams 23, anddifferent sized fabric 10,40. The thickness of the fabric 10,40 dependson its area in the wetsuit 20 and can be varied by adjusting thethickness of the layer of neoprene 15. For example, the thickness of thefabric 10,40 could be greater in torso and back areas 25 than in arm andleg areas 27. For high mobility areas like elbows and knees 28, thethickness of fabric 10,40 could be lesser as compared to the otherareas. For areas like arm pits 29 and groin, the intermediate layer ofneoprene 15 may not be present.

While it is preferred that a wetsuit or similar garment is formed whollyfrom fabric according to the present invention, it is also contemplatedthat a wetsuit may have panels or sections of fabric according to thepresent invention, and sections which are of other construction, forexample simple neoprene. Other garments, for example boots, hoods,vests, etc may be constructed from the fabric. The fabric may also beused for other applications other than garments where shark resistanceis desired.

It will be appreciated that the thicknesses of layers discussed are thepresently preferred form, however, many different thicknesses could beused, subject to effectiveness and practicality. For example, the outerand inner layers may be of different thicknesses, and the intermediatelayer may be varied in thickness for different conditions or usages. Thepresent invention may be applied to a wetsuit fabric of any suitablethickness, or to applications such as drysuits in which the neoprene isformed from crushed neoprene material and an additional fleece or otherlayer is provided inside the suit.

Sharks are curious when they encounter something unusual, such as adiver or swimmer. Their way to explore an object, or potential prey, isto bite it; these bites are known as test bites. Generally, shark biteson humans are exploratory, and the animal will swim away after one bite.Many exploratory bites on surfers may be caused by the shark mistakingthe surfer and surfboard for a seal or other prey. These bites aregenerally not at full bite force, but if delivered by a large shark,significant injury is likely.

Large predatory sharks generally have multiple rows of triangular shapedteeth, with serrated surfaces. FIG. 4a shows a single shark tooth 30with serrations 31 in initial contact with the fabric 10. FIG. 4b showsthe single shark tooth 30 being depressed into fabric 10, and contactingthe outer layer of woven or knitted UHMwPE material 11. It has beenobserved in trials of implementations of the present invention that theshark in some cases does not complete a test bite after contact with thewoven or knitted outer UHMwPE layer 11. It is postulated that the teethengage with the fabric in a way that the shark finds unfamiliar,inconsistent with prey, or in some other way terminates the test bitebehaviour. This may be because the serrations on the teeth catch orengage with the outer fabric.

In some trials, it has been observed that some sharks will make a moredetermined, full strength bite, particularly if blood and otherattractive scents are in the water. In trials, the teeth of the shark 30in some cases penetrated the outer layer 11 and the neoprene 15, but didnot penetrate the inner UHMwPE layer 13. Whilst it cannot be said thatit is not possible for a shark to penetrate the full thickness of thematerial used in this example, it certainly appears to greatly reducethe risk of such penetration. It will be appreciated that while theremay still be injury from a non-penetrating bite, it is much less likelythat there will be blood in the water to excite the attacking shark orother sharks, and much less likely that the victim will experience thecatastrophic blood loss which is often the cause of death from a sharkbite.

While UHMwPE material is presently preferred, it is contemplated thatthe present invention could be implemented using alternative fibres, orin a mixed fibre fabric, for example with fibreglass, polyester, orother known or yet to be developed materials. The fabric must providethe desired levels of bite resistance, however, other factors such aswearability, having sufficient flexibility and comfort to allow forpractical use by divers and surfers, are also important for a practicalimplementation.

The term neoprene is used in the general sense to mean any kind ofsynthetic rubber material which is suitable for the present application.It will generally have a degree of buoyancy relative to water. It willtypically be a closed cell foam, but may be formed from crushed neopreneor other materials. The precise composition of the neoprene layer is notcritical to the inventive concept.

The reference in this specification to any prior publication (orinformation derived from it), or to any matter which is known, is not,and should not be taken as an acknowledgment or admission or any form ofsuggestion that the prior publication (or information derived from it)or known matter forms part of the common general knowledge in the fieldof endeavour to which this specification relates.

All patent and other references cited above are hereby incorporated byreference into the specification.

1-14. (canceled)
 15. A shark resistant composite fabric adapted for usein a garment, the fabric comprising: an outer layer of shark biteresistant material, an intermediate layer of neoprene, and an innerlayer of a shark bite resistant material, the shark bite resistantmaterial being formed from a woven or knitted layer of UHMwPE material.16. The shark resistant composite fabric adapted for use in a garmentaccording to claim 15, further comprising fiberglass and/or polyester,wherein in the event of a shark attack, a contact of the shark's toothwith the outer layer resists or deters the completion of a test bite.17. A shark resistant composite fabric according to claim 15, whereineach of the outer and inner layers has a thickness of about 1.2 mm. 18.A shark resistant composite fabric according to claim 15, wherein theintermediate layer has a thickness in the range of about 1 to about 7mm.
 19. A shark resistant garment, the garment being formed using afabric comprising: an outer layer of shark bite resistant material, anintermediate layer of neoprene, and an inner layer of a shark biteresistant material, the shark bite resistant material being formed froma woven or knitted layer of UHMwPE material.
 20. The shark resistantgarment according to claim 19 further comprising fiberglass and/orpolyester, wherein in the event of a shark attack, a contact of theshark's tooth with the outer layer resists or deters the completion of atest bite.
 21. A shark resistant garment according to claim 19, whereineach of the outer and inner layers has a thickness of about 1.2 mm. 22.A shark resistant garment according to claim 19, wherein theintermediate layer has a thickness in the range of about 1 to about 7mm.